High-pressure boiler for steam locomotives



Dec. 1, 19 36. H. 'NYFFENEGGER El ALIF ,06 ,6

HIGH PRESSURE BOILER FOR STEAM LOCOMOTIVES F iled Aug. 24, 1954 2 SheetsSheet l N N1; 1 Q jaw/339211 \a 44 v A a/M 1 N zfmmmm E R j? Patented Dec. 1, 1936 UNITED STATES HIGH-PRESSURE BOILER FOR STEAM LOCOMOTIVES Hans N yflenegger and Hans Sigrist; Winterthur,

Switzerland, assignors to the firm Schweizerische Lokomotiv- & Maschinenfabrik, Winterthur, Switzerland Application August 24,

In Germany 6 Claims.

The present invention relates to improvements in high-pressure boilers for steam locomotives. It is a well known fact that it presents difiiculties to design the superheater or the superheaters of high-pressure locomotive-boilers so that they respond to the thermotechnical, constructional and service requirements and to arrange them in the smoke-box part of the boiler. The present invention deals with this problem and provides a novel and, favorable construction and arrangement of a superheater chamber conducting and inclosing the current of the flue gases and the arrangement and disposition of the superheater tubes within this superheater chamber.

It has already been proposed to insert the superheater elements laterally between the vertical ascending evaporator tubes of a tube boiler and to fix said elements on webs welded to said tubes or by means of clamps. Further it is'knOWn to support the whole group of superheater tubes by a structure suspended from the upper steam drum and to insert it also sideways into the boiler.

These constructions present the disadvantage that the structural parts i. e. the webs welded to the water tubes or the clamping means supporting the bundle of superheater tubes are insufiiciently cooled or are not cooled at In the superheater chambers constructed in this manner temperatures of between 900 and 1100 C. have to be expected, so that the supporting parts are soon deformed and are completely destroyed by burning unless they are made of a specially heat resisting and very expensive material. Furthermore the superheater tubes are damaged at the small contacting faces of the webs supporting the tubes owing to the shocks and vibrations occurring on a running locomotive. These known constructions show the further drawback that the insulation of the boiler is soon destroyed as on one hand the webs laterally defining the flow of current of the flue gases assume a high temperatureand on the other hand the insulation above the superheater tubes is only supported at inter- 45 vals by the evaporator tubes and is thus exposed in an excessive manner to the direct radiation and contact of the flue gases.

All the aforementioned disadvantages are overcome by the superheater constructed according 50 to the present invention inasmuch as the superheater tubes are supported with large bearing surfaces in the water-cooled stay tubes of water filled plate walls, the latter limiting laterally the superheater chamber. The floor and the roof 5i oi this chamber may, for instance, be formed by 1934, Serial No. 741,306 August 26, 1933 ranges of tubes contacting with each other and inserted in this chamber or also by water filled plate walls, whereby the insulation of the boiler and the upperdrums is securely protected against destruction and radiating heat. The lateral insulation is also almost completely screened by the water filled plate Walls and protected against destruction, in opposition to the second of the above mentioned known proposals in which a large surface of the boiler insulation on the side from which the superheater is brought into the boiler is directly exposed to the flue gases. This second proposal in comparison to the first mentioned proposal shows the advantage, of a good accessibility of the interior of the boiler after removal of the superheater tubes; the subject matter of the present application, however, combines at the same time an excellent screening of the lateral parts of the boiler insulation with the good accessibility of the inner parts-of the boilerafter the removal of the superheater tubes together with the water :filled plate walls.

constructional examples of the subject matter of the invention are illustrated on the accompanying drawings, in which Fig. 1 shows in a vertical longitudinal section a high pressure locomotive boiler;

Fig. 2 is a cross-section along line II-II in Fig. 1;

Fig. 3 shows the superheater chamber in a section along line I-II'-III in Fig. 1;

Fig. 4 is a section along line IV-IVin-Fig. 3;

.Fig. 5 is a modifiedsuperheater chamber shown ina similar section as Fig. 3;

Fig. 6 is a section along line VI- VI in Fig. 5;

Fig. 7 is a sideelevation of Fig.6;

Fig. 8 shows a further modificationof the superheater chamber.

The steam. generating portion of the highpressure locomotive boiler illustrated in .Fig. 1 comprisestwov upper drums a, two lower drums b of the fire box, two lower'drumsc of the combustion chamber which are connected together by water filled :plate walls 011,112 and d3 stiffened by stay tubes d4. Obviously the .number of the drums may vary. These plate walls .011, dz, do serveas supporting structure of theboiler and at the same time asdowncomers in the water circulation. Each of the evaporator elements e consists, as is shown in Fig. 2; of two vertical or nearly vertical and one nearly horizontal evaporator tube. The horizontal and vertical branches are connected by corner pieces or, carrying at their outer ends removable screw caps e: for :cleaning purposes. All the evaporator elements care placed side by side in close contact and form the lateral walls of the fire box and the roof of the latter which protects the upper drums against the radiating heat of the fire. Short branch tubes ,f conduct the generated steam to the upper drums a. The floor of the fire box is formed by the grate. In the front portion of the fire box F two longitudinal rows of evaporator tubes 9 are provided which largely increase the heating surface of the fire box and act at the same time as supports for the arch h. The combustion chamber K is provided with water tubes similar to those in the fire box, however, the water tubes are only arranged in the rear part of the combustion chamber, the front part thereof being without water tubes to leave room for the insertion of the watercooled superheater chamber U.

To the foremost plate wall d3 of the high-pressure steam generator joins a low-pressure smoke tube feed water preheater V in the smoke tubes 1'1 of which the tube coils T2 of a high-pressure feed water preheater are disposed.

The superheater chamber illustrated in detail in Figs. 3 and 4 is formed by two lateral vertical or nearly vertical water filled plate walls 2' which are stiffened by large stay tubes 1 and are supported by the lower drums similarly to the walls d1, d2 and 123. The floor and the roof of the superheater chamber U are each formed by a horizontal or nearly horizontal row of water tubes k1 and k2 respectively, which are in open connection with the water contents of the lateral walls 2 through holes 111. The large stay tubes 1 of the lateral walls 2 of the chamber serve for supporting a tube bundle m comprising a plurality of superheater tubes, which may be placed in position and removed from the sides of the locomotive through an opening in the boiler shell 12 which is closed by a sheet metal plate w. The interconnection of the bundles m of superheater tubes and the arrangement of the entrance and exit collecting pipes 10 is efiected outside of the superheater chamber in any suitable manner. In Fig. 4, for instance, all the bundles situated in a vertical row are connected in series and united to a single pipe which is connected at top and bottom to the collectors p.

In the modified example of the superheater chamber U illustrated in Figs. 5 and 6 the lateral walls are formed by plate walls 2' stiffened by small stay tubes 11.. Every two stay tubes of the opposite plate walls serve for supporting one superheater tube which can be brought into position and removed from the sides of the locomotive. The connection of the single superheater tubes and the arrangement of the entrance and exit collectors p may be made in any suitable manner.

In order to protect the superheater tubes m and 0 respectively against getting red hot, particularly when the withdrawal of steam from the superheater has been interrupted, on the flue gas entrance side of the superheater chamber U one or more vertical rows of approximately horizontal water tubes q are provided which are in open communication with the water filled side walls of the superheater chamber U by openings :02 and which are provided with removable caps pa for cleaning purposes in a similar manner as the tubes in, kg. This arrangement is illustrated in Figs. 6} and 7. Obviously instead of the horizontal tubes q vertical tube rows interposed between the tubes forming the floor and the roof of the superheater chamber serve the same purpose.

The water cooled superheater chamber U may be connected up to the low pressure feed water preheater V for instance by pipes a1 and qz shown in Fig. 1 and may thus be subjected to a pressure of, for instance, 10 to atmospheres, however the chamber U may be connected up to the tube coils T2 of the high pressure feedwater preheater or to the high pressure boiler and be subjected to a pressure of 60 atmospheres. In case there is an appropriate feed water preheater system provided the superheater chamber U may be cooled by means of water whose pressure is little above atmospheric pressure.

As the whole superheater chamber U together with the superheater tubes m and n respectively may be brought into position and removed from the sides of the locomotive an excellent accessibility of this part of the boiler is obtained. The superheater chamber according to the invention may also be utilized in combination with other boiler systems than that shown in Fig. 1, for instance, with such in which the low pressure preheater is omitted and replaced by a continuation of the high-pressure tube boiler part.

It may be advantageous not to make the lateral plate walls as shown in a single piece but. to subdivide same in horizontal or vertical direction.

The insertion of the superheater elements may also be effected from both sides of the locomotive, in which case the support of the returning ends of the tubes is efiected by an intermediate plate wall 11 as is illustrated in Fig. 8. This intermediate plate wall may also be provided in case a middle support of the superheater tubes shown in Figs. 3 and 5 is desired. The wall it is supported on a third lower drum 01.

The arrangement and the interconnection of the superheater tubes are obviously not restricted to those shown in Figs. 3-6. For instance the horizontal rows of the superheater tubes could be connected in series and alternately joined to collecting tubes such as p arranged on the right and left hand side of the superheating chamber.

We claim:

1. In a high-pressure locomotive boiler, a superheater chamber, water filled plate walls forming the lateral walls of said chamber, stay tubes for stiffening said plate walls, superheater tubes supported by said plate walls, and water tubes forming the bottom and the ceiling of said chamber, said water tubes communicating with the water content of said plate walls.

2. In a high-pressure locomotive boiler, a shell provided with an opening, double walls forming a self-contained superheater chamber inserted in the flue forwardly of the fire box through said opening in said shell, superheater tubes extending through said chamber transversely to the flow of furnace gas in continuous lengths, said double walls constituting water-filled plate walls providing at least the side walls of said chamber, and bearing sleeves for said tubes at corresponding points of opposite tube supporting plate walls extending between the plates of each of said walls and contacting with said tubes and the water content of said walls with their inner and outer peripheral surfaces respectively, said sleeves supporting said superheater tubes inserted therein and removable through said side walls.

3. In a high-pressure locomotive boiler, a shell provided with an opening, double walls forming a self-contained superheater chamber inserted in the flue forwardly of the fire box through said opening in said shell, superheater tubes extending through said chamber in bundles transversely to the fiow of furnace gas in continuous lengths, said double walls constituting water-filled plate walls providing at least the side walls of said chamber, and superheater tube receiving stay tubes having a large diameter and adapted to stiffen said plate walls at corresponding points of opposite tube supporting Walls and contacting with individual bundles of said superheater tubes and the water content of said walls with their inner and outer peripheral surfaces respectively, said stay tubes supporting said superheater tubes inserted therein and removable through said side walls.

4. In a high-pressure locomotive boiler, a shell provided with an opening, double walls forming a self-contained superheater chamber inserted in the flue forwardly of the fire box through said opening in said shell, superheater tubes extending through said chamber transversely to the flow of furnace gas in continuous lengths, said double walls constituting water-filled plate walls providing at least the side walls of said chamber, and superheater tube receiving stay tubes having a small diameter and adapted to stiffen said plate walls at corresponding points of opposite tube supporting plate walls and contacting with individual superheater tubes and the water content of said walls with their inner and outer peripheral surfaces respectively, said stay tubes supporting said superheater tubes inserted therein and removable through said side walls.

5. In a high-pressure locomotive boiler, a shell provided with an opening, double walls forming a self-contained superheater chamber inserted in the flue forwardly of the fire box through said opening in said shell, superheater tubes extending through said chamber transversely to the flow of furnace gas in continuous lengths, said double walls constituting water-filled plate walls providing at least the side walls of said chamber, bearing sleeves for said tubes at corresponding points of opposite tube supporting plate walls extending between the plates of each of said walls and contacting with said tubes and the water content of said walls with their inner and outer peripheral surfaces respectively, said sleeves supporting said superheater tubes insertedthereinand removable through said side walls, and at least one row of water tubes intercommunicating with said side walls at the entrance end for the furnace gas of said chamber for screening said superheater tubes against undue heating by the flow of said gas.

6. In a high-pressure locomotive boiler, a shell provided with an opening, double walls forming a self-contained sumrheater chamber inserted in the flue forwardly of the fire box through said opening in said shell and removable therefrom through said opening laterally of the locomotive, superheater tubes extending throughsaid chamber transversely to the flow of furnace gas in continuous lengths, said double walls constituting water-filled plate walls providing at least the side walls of said chamber, and bearing sleeves for said tubes at corresponding points of opposite tube supporting walls extending between the plates of each of said walls and contacting withsaid tubes and thewater content of said walls with their inner and outer peripheral surfaces respectively, said sleeves supporting said superheater tubes inserted therein and removable through said side walls.

HANS NYFFENEGGER. HANS SIGRIST. 

